PeterDonis's latest activity
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PeterDonis replied to the thread A 1-Way Speed of Light.More precisely, the geometry of the surfaces of constant Schwarzschild coordinate time is not Euclidean, and that is the coordinate... -
PeterDonis replied to the thread A 1-Way Speed of Light.Clock synchronization is inherent in any experiment to measure the one-way speed of light, which is the very title of this thread. So...
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PeterDonis replied to the thread A 1-Way Speed of Light.No, it won't. Ideally it will be 180 degrees, since A and B are on opposite sides of the wheel. No, opposite directions. No, they...
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PeterDonis replied to the thread I Eddington’s margin of error.And I think it's fair to say that Eddington's prestige precluded any real review of the results at the time. They were just accepted.
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PeterDonis replied to the thread A Physical properties of the vacuum in GR vs. QFT.I don't think there is a "canonical" process by which the community does this. Every physicist has their own opinion about it. Consider...
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PeterDonis replied to the thread A Physical properties of the vacuum in GR vs. QFT.Still not as powerful as predicting a new effect that hasn't been observed before, and having that prediction confirmed. Note that...
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PeterDonis replied to the thread I Understanding the historical shift away from absolute simultaneity.That's out of bounds here. We can't discuss imagined theories. We can only discuss theories that have actually been published in the...
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PeterDonis reacted to Anton Rize's post in the thread A Is there any topology behind factor 2 in Schwarzschild radius? with
Like.
Thanks all — that answers my curiosity. I see now that in standard GR the “2” is fixed by the Newtonian limit and shows up in the... -
PeterDonis replied to the thread I MTW exercise 21.26: junction conditions for a thin shell of dust.Yes, that's the physical interpretation of the result. How did you derive equation (c)?
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PeterDonis replied to the thread I Understanding the historical shift away from absolute simultaneity.There wasn't just one. There were various proposals for ether theories, assigning different properties to the ether (for example...
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PeterDonis replied to the thread I MTW exercise 21.26: junction conditions for a thin shell of dust.What do you get if you add the second and third equations?
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PeterDonis replied to the thread I Modern View of Quantum Phenomena.An effective theory is one that is admitted to not be fundamental. Or, if you insist on a definition that doesn't use either of those...
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PeterDonis replied to the thread I Understanding the historical shift away from absolute simultaneity.There is no such thing. LET, as I've said, is SR, plus the claim that there's an unobservable absolute reference frame. It has to use...
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PeterDonis replied to the thread A Is the constancy of c a postulate or a derivable theorem?.That's how I understand it as well. And the fact that Maxwell's Equations were Lorentz invariant rather than Galilean invariant was...
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PeterDonis replied to the thread I Understanding the historical shift away from absolute simultaneity.If someone ever comes up with a theoretical model that includes such a testable prediction, then we can test it and see. But LET is not...